Originally posted by AndrewT Hi,
yes, post141 schematic is the one where both C4 & C6 are shown and you discuss the offset problem if C4 is omitted. Mixed AC & DC coupling with the unmatched resistances explains all.

Well Andrew, you motivated me to try again.
My fatal flaw the first time was running all of the simulations with the input unconnected.

Another rookie mistake. With the input grounded or connected to a signal, I have the offset down to 50mV range and with your suggested change to R15 (from 2.2K to 500R), 6-7mV.
Another lesson learned.

It looks like "proper" CCS's are popping up everywhere..
(reproducing) ...And hey ...a buffered widlar CM
(betcha it gets 70-80 db gain now)
and a CFP input . Whoaaa...
Happy New Year (NY) ...I used to live there
OS

Edit: U5 and U1 emitters need a 33R across them.. then you will
have a"leach" OP..